Biopesticide delay plagues malaria control plan
A TUSSLE over registration procedures for two new kinds of pesticides that could form the cornerstone of India's malaria eradication programme has ended, but the question of which one will be used is likely to be decided only much later, and this is adversely affecting the malaria eradication programme.
The two kinds of pesticides are deltamethrin, a synthetic pyrethyroid manufactured by Rousel Chemicals, and two biopesticides. Registration with the Central Insecticide Board (CIB) is a prerequisite for importing and using pesticides in India. While Rousel had no trouble registering deltamethrin, as guidelines for chemical pesticides had been specified some time ago, the Malaria Research Centre (MRC) in New Delhi faced delays in getting the two biopesticides registered because their registration procedures were finalised only in mid-September.
Says Salil Singhal, chairman of the Pesticides Association of India, "The question is what kind of approach the country should take for registering pesticides and biopesticides." For instance, the EC treats all pesticides identically and, unlike USA, does not extend any concessions to biopesticides.
The controversy on the choice of pesticides for the anti-malaria programme is heating up. "Both deltamethrin and biopesticides are being field-tested and no results are expected for the next two years," says director of the National Malaria Eradication Programme, HVVL Narasimhan. The currently used pesticides, DDT, BHC and malathion, have to be replaced because of increasing resistance by mosquitoes to them. The Union health ministry reports malaria cases increased from 1.66 million in 1987 to 1.89 million in 1990.
Deltamethrin, a synthetic version of an extract from the chrysanthemum plant, is more effective and lasts longer than the pesticides currently in use. Though Rousel has conducted field trials since 1986 in India, the government has not cleared deltamethrin for mass use. Extensive trials of deltamethrin were conducted from 1985 to 1988 by both the National Institute of Communicable Diseases and MRC which found that the incidence of malaria dropped sharply after spraying.
Not target-specific
But MRC director V P Sharma says deltamethrin is not target-specific like biopesticides, which means it can kill mosquitoes as well as beneficial insects. It is also not very effective against the Culex species of mosquitoes and during field trials, workers complained of skin irritation.
Counters C J Babu, a senior scientist at Rousel, "Deltamethrin has been tested in India as per the guidelines of the World Health Organisation and found safe for mass application. It is used in malaria control programmes in Guatemala, the Philippines, Congo and China."
Counters C J Babu, a senior scientist at Rousel, "Deltamethrin has been tested in India as per the guidelines of the World Health Organisation and found safe for mass application. It is used in malaria control programmes in Guatemala, the Philippines, Congo and China."